if a change releases this, it is more than likely a chemical change?
heat
light
and some others (including formation of a precipitate and the formation of a gas but these aren't formed in the sense of being released).
To determine whether a change is a chemical change or not, you can consider a few factors. In this case, we can analyze the examples you provided:
1. Heat: Heat can be a product of a chemical reaction, but it can also be a result of a physical change, such as melting or dissolving. To determine if the heat is a result of a chemical change, you can consider if any new substances are being formed during the process. If so, it is likely a chemical change.
2. Light: Light can also be a product of both chemical and physical changes. For example, light can be generated during a chemical reaction, like in a combustion reaction. On the other hand, light can also be produced during a physical process, such as shining a flashlight or breaking a glow stick. Again, you need to consider if any new substances are being formed to determine if it is a chemical change.
3. Formation of a precipitate: When two solutions are mixed, a precipitate can form if there is a chemical reaction occurring between the compounds. This is an example of a chemical change since it involves the formation of a new solid substance.
4. Formation of a gas: Similar to the precipitation example, the formation of a gas can indicate a chemical change. It usually occurs as a result of a chemical reaction between different substances.
To summarize, while heat and light can be produced in both chemical and physical changes, the formation of a precipitate or the generation of a gas are more likely indicators of a chemical change since they involve the formation of new substances. It's always important to consider the overall context of the reaction and any apparent chemical transformations taking place.